title: Mechanism of dual specificity kinase activity of DYRK1A.
abstract: The function of many protein kinases is controlled by the phosphorylation of a critical tyrosine residue in the activation loop. Dual specificity tyrosine-phosphorylation-regulated kinases (DYRKs) autophosphorylate on this tyrosine residue but phosphorylate substrates on aliphatic amino acids. This study addresses the mechanism of dual specificity kinase activity in DYRK1A and related kinases. Tyrosine autophosphorylation of DYRK1A occurred rapidly during in vitro translation and did not depend on the non-catalytic domains or other proteins. Expression in bacteria as well as in mammalian cells revealed that tyrosine kinase activity of DYRK1A is not restricted to the co-translational autophosphorylation in the activation loop. Moreover, mature DYRK1A was still capable of tyrosine autophosphorylation. Point mutants of DYRK1A and DYRK2 lacking the activation loop tyrosine showed enhanced tyrosine kinase activity. A series of structurally diverse DYRK1A inhibitors was used to pharmacologically distinguish different conformational states of the catalytic domain that are hypothesized to account for the dual specificity kinase activity. All tested compounds inhibited substrate phosphorylation with higher potency than autophosphorylation but none of the tested inhibitors differentially inhibited threonine and tyrosine kinase activity. Finally, the related cyclin-dependent kinase-like kinases (CLKs), which lack the activation loop tyrosine, autophosphorylated on tyrosine both in vitro and in living cells. We propose a model of DYRK autoactivation in which tyrosine autophosphorylation in the activation loop stabilizes a conformation of the catalytic domain with enhanced serine/threonine kinase activity without disabling tyrosine phosphorylation. The mechanism of dual specificity kinase activity probably applies to related serine/threonine kinases that depend on tyrosine autophosphorylation for maturation.
authors.affiliation: Institute of Pharmacology and Toxicology, RWTH Aachen University, Germany.
authors.forename: Agnes
authors.initials: A
authors.lastname: Walte
authors.forename: Katharina
authors.initials: K
authors.lastname: Rüben
authors.forename: Ruth
authors.initials: R
authors.lastname: Birner-Gruenberger
authors.forename: Christian
authors.initials: C
authors.lastname: Preisinger
authors.forename: Simone
authors.initials: S
authors.lastname: Bamberg-Lemper
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Hilz
authors.forename: Franz
authors.initials: F
authors.lastname: Bracher
authors.forename: Walter
authors.initials: W
authors.lastname: Becker
mesh_terms: D000818:Animals; D055162:Biocatalysis; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D013816:Thermodynamics; D013912:Threonine / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D014443:Tyrosine / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000097603:Dyrk Kinases
chemical_list: D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases; D011994:Recombinant Proteins; D012694:Serine; D013912:Threonine; D014443:Tyrosine; D000097603:Dyrk Kinases
keywords: DYRK; HIPK2; iodotubercidin; kinase inhibitors; tyrosine autophosphorylation